How long to image the Tarantula Nebula with the ZWO Seestar S50
From a Bortle 6 suburban sky, the ZWO Seestar S50 needs about 32 min (190 subs of 10 s with the built-in dual-band (LP filter) filter) for a solid image of the Tarantula Nebula. A quick look takes 8 min; a showpiece 2 h 07 min. Under a Bortle 3 rural sky the solid figure drops to 23 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it only just fits, at 93% of the short side.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 6 min34 subs | 22 min134 subs | 1 h 29 min534 subs |
| Bortle 2Typical dark site | 6 min34 subs | 23 min136 subs | 1 h 30 min541 subs |
| Bortle 3Rural | 6 min35 subs | 23 min139 subs | 1 h 32 min554 subs |
| Bortle 4Rural / suburban transition | 6 min37 subs | 24 min147 subs | 1 h 38 min586 subs |
| Bortle 5Suburban | 7 min40 subs | 26 min159 subs | 1 h 46 min636 subs |
| Bortle 6Bright suburban | 8 min48 subs | 32 min190 subs | 2 h 07 min760 subs |
| Bortle 7Suburban / urban transition | 10 min63 subs | 41 min249 subs | 2 h 46 min995 subs |
| Bortle 8City | 14 min85 subs | 57 min340 subs | 3 h 47 min1,360 subs |
| Bortle 9Inner city | 22 min134 subs | 1 h 29 min535 subs | 5 h 56 min2,139 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 41 min of run time. The Seestar S50’s battery (rated about 6 h) should cover it; a power bank still keeps the phone running the app alive. (Bortle 6, solid image; we allow 30% over the integration time, and 30% off the battery for a December night.)
- USB-C power bank 20000mAh 5V 3AThe S50 draws 5 V 3 A over USB-C and runs while charging; no PD needed.
- Seestar S50 dew shieldThe built-in heater copes with most nights; a shield helps in heavy dew and blocks stray light.
- red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
- hand warmers long lastingAir-activated packs give hours of heat for the person; winter nights are long and you spend most of them standing still.
Affiliate links: the retailer pays us a small commission and you pay the same price. These are search links to the named product, not endorsements of a particular listing; check the listing matches your model.
Everything that fits the Seestar S50 →
How it frames
The Tarantula Nebula is 40′ × 25′ across. The Seestar S50 frames 1.28° × 0.72° at 2.39″ per pixel, so it only just fits, at 93% of the short side. Centre it carefully: there is no room to crop back afterwards.
Longer subs
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode (app 2.5 and later). Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 23 min139 subs | 26 min159 subs | 41 min249 subs |
| 20 s | 18 min54 subs | 21 min64 subs | 36 min109 subs |
| 30 s | 16 min32 subs | 19 min39 subs | 34 min69 subs |
| 60 s | 30 min30 subs | 30 min30 subs | 33 min33 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| UV/IR-cut (no light-pollution filter) | 19 min116 subs | 30 min183 subs | 1 h 19 min476 subs |
| dual-band (LP filter) | 23 min139 subs | 26 min159 subs | 41 min249 subs |
About the Tarantula Nebula
The giant star-forming region in the Large Magellanic Cloud, bright enough to see naked-eye from another galaxy. Far south only.
NGC 2070, Caldwell 103, 30 Doradus · Emission nebula in Dorado · magnitude 8.0 · 40′ × 25′ · best in Nov, Dec, Jan. Southern hemisphere only.
Emission nebulae glow in a few narrow lines, mostly hydrogen-alpha (deep red) and doubly ionised oxygen (teal). A dual-band filter passes those lines and blocks most skyglow, which is why it cuts the time needed from a suburban sky so dramatically. Use it. From a genuinely dark site the gain is smaller because there is less skyglow to block, and read noise becomes the limit, which is where longer subs (EQ mode, or Expert Mode on a Vespera) earn their keep.
Stars lose colour through a dual-band filter; a short broadband stack blended in fixes that if you care.
About the ZWO Seestar S50
The scope that made smart astrophotography mainstream. 50 mm triplet, 2 MP sensor, dual-band filter on a wheel. Alt-Az stacking at 10 s, EQ mode unlocks 60 s. Out of production since 2026 and replaced by the S50 Pro, but there are a great many in use.
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode (app 2.5 and later). Built-in dual-band light-pollution filter, switchable in the app.
Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 10 s and 60 s subs is small; from a rural site it can halve the total time, especially with a dual-band filter in place.
Stack across nights. Every smart scope app can continue a stack or you can combine the saved frames on a computer; the figures here are totals, not single-session limits.
Have an image of the Tarantula Nebula from a Seestar S50? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Tarantula Nebula with the ZWO Seestar S50 Pro: 35 min from Bortle 6
- Tarantula Nebula with the ZWO Seestar S30: 36 min from Bortle 6
- Tarantula Nebula with the ZWO Seestar S30 Pro: 38 min from Bortle 6
- Tarantula Nebula with the DwarfLab DWARF 3: 40 min from Bortle 6
- Tarantula Nebula with the DwarfLab DWARF mini: 31 min from Bortle 6
- Tarantula Nebula with the DwarfLab Draco: 25 min from Bortle 6
- Tarantula Nebula with the DwarfLab DWARF II: 2 h 41 min from Bortle 6
- Tarantula Nebula with the Vaonis Vespera II: 47 min from Bortle 6
- Tarantula Nebula with the Vaonis Vespera Pro: 1 h 46 min from Bortle 6
- Tarantula Nebula with the Vaonis Vespera 3: 45 min from Bortle 6
- Tarantula Nebula with the Vaonis Vespera Pro 2: 1 h 41 min from Bortle 6
- Tarantula Nebula with the Unistellar eQuinox 2: 42 min from Bortle 6
- Tarantula Nebula with the Unistellar Odyssey: 3 h 15 min from Bortle 6
- Tarantula Nebula with the Celestron Origin: 13 min from Bortle 6
- Tarantula Nebula with the Celestron Origin Mark II: 17 min from Bortle 6
All telescopes for the Tarantula Nebula · All targets for the Seestar S50